“Chapter 5” is easily the best episode of Legion since the pilot and very possibly the best episode of FX’s X-Men series so far. It feels like the past four episodes, with their myriad of horrors and mysteries, have all been leading to this. So let’s just dive right in.

This Week in David and Syd

You know things are about to get really bad on Legion when the scenes between David and Syd, usually the respite from the horrors pouring out of the rest of the plot, become a key source of dread and tension. That cute banter, their oddball flirtation, the charming chemistry between Dan Stevens and Rachel Keller, has only set us up to fall and fall hard.

And at first, things seem to be going so well. David returns from his trip to the Astral Plane with newfound confidence and control over his powers. For the first time since we met him, he appears to have his act together. He’s even able to create a psychic space, the “white room,” where Syd can visit and the two of them can be intimate for the first time. It should be lovely. It should be sweet and romantic. But then that camera pans over, revealing a bowl of fruit covered in bugs. And then Syd explains the details her first sexual encounter, a body-swapping nightmare involving her mom and her mom’s boyfriend. It’s telling that Legion does not let David and Syd’s first moment of actual physical affection exist as a purely sweet moment – once their relationship becomes real, once the personal truths start to pour out of Syd, the unpleasant truths begin to pour out of David. Just in a much more literal, much more dangerous fashion.

Working With the Monsters

We quickly learn the source of David’s newfound confidence. As we saw last week, he only managed to escape the Astral Plane by working directly with Aubrey Plaza‘s Lenny, one of several figments living inside his mind. Now that he’s embraced his inner demons, now that their interactions are collaborations rather than struggles, David has become exactly what Dr. Bird was hoping he would be – a powerful mutant who can harness his powers.

Kind of. Sort of. Because David also appears to have surrendered a great deal of control in the process. Now, Lenny, the devil with the yellow eyes, and the rest of the monsters living in the red bathroom adjacent to the white room (including King the Beagle and the World’s Angriest Boy in the World) have stepped up to help run the mind they call home.

The Summerland crew is still at odds over what’s going on in his mind. Is David actually schizophrenic? Is he victim of another, more powerful force that has taken control of his psyche? Or is it a little bit of both, an unwell man being pillaged by a rogue mutant mind taking advantage of his insecurities and weaknesses?

No matter the truth, there’s no denying just how real and how uncomfortable David’s situation feels despite the comic book trappings. In past episodes, Dan Stevens has offered one of the more nuanced portrayals of mental illness we’ve seen on television. Not every day is bad day. Not every moment is one of a terror and dread. You still laugh and you still fall in love and you still live your life, albeit with something awful lurking just over your shoulder. David’s surge of confidence, his mania over being in control for the first time ever, leads directly to those shattering final scenes, where he is as helpless as we’ve ever seen him. For all of its style, Legion never loses sight of its central plight and Stevens continues to bring the goods.

A Rescue Mission and a Murder Spree

With his newfound control, David (or rather, David and his interior accomplices) sets out to rescue Amy from Division 3’s prison. He leaves Summerland in the middle of the night, while the rest of the crew is planning the operation. He doesn’t need them.

And we soon see why. As the rest of Legion‘s cast arrives, they find dozens of dead soldiers, some phased through walls and floors, others just blown to pieces. It’s the show’s grand return to horror after tapping the brakes in favor of mystery and cosmic weirdness last week – we’re spared the action scene because it’s not an actual action scene. It’s a murder spree, and we’re only granted quick glimpses of it in security camera footage. Legion does what few other comic book adaptations would dare to do: acknowledge that someone with telekinetic powers is nothing short of terrifying.

The Summerland crew’s descent into the Division 3 prison is disorienting. As they navigate the maze of mangled bodies, edits are hidden within the momentary darkness of flickering lights, lending an unease to the scene. It’s one of the most unsettling moments in Legion so far and it’s not even the most unsettling sequence in the episode. For all of its quirks, for all of its comic book touches, for all of its stylistic choices and eccentric characters, Legion is still a horror story at the end of the day and “Chapter 5” is one of its finest hours on this front.

And those infrared shots revealing that the devil with yellow eyes is really in the driver’s seat throughout the assault? Terrifying.

Welcome Home

David is adopted. Comic book readers knew this. The identity of his father isn’t a secret and a quick Google search will tell you more, but since the show is keeping it under wraps, we will, too. But David doesn’t seem to take the news well and suddenly, Amy seems to be in actual danger. Will the monsters, the voices, the alternate personalities that call him home, extend protection over someone who is not his flesh and blood? The tethers that keep David grounded (Summerland, Amy, Syd) are fraying. The only constant, the only person who seems to really have his ear at this point, is Lenny.

The final stretch of “Chapter 5,” where the Summerland crew arrives at David’s childhood home and finds themselves immediately at the mercy of his god-like powers, may be the best scene in Legion so far. It’s an exquisite blend of horror and dark comedy: David removes all sound from the area, replacing all dialogue and music with an eerie drone. Unable to communicate, the group quickly fractures. Watching everyone shout in silence, watching Cary and Kerry arrive and attempt to explain themselves in pantomime, feels like a waking nightmare.

And at the end of the nightmare is Lenny, who has decided to dress up for the occasion. The filthy junkie is gone and the scheming mastermind has revealed herself. That the devil with the yellow eyes wears a similar suit could suggest that these two are one and the same…or it just implies that David’s monsters coordinate their wardrobes. Whatever these things are, an outside force or a side effect of our protagonist’s psyche, they’re in control now and David has been reduced to a mere vehicle. The most powerful weapon on the planet has been hijacked.

It cannot be overstated how good Plaza is here, using her laid-back, sarcastic charm to infuse every Lenny moment with a mocking humor. This thing is having a great time. It’s not going to give up control without a fight.

A Super Villain Origin Story?

“Chapter 5” is the darkest and most terrifying hour of Legion yet and the best episode since the pilot. And it also is the first to truly suggest that we’re not watching a television show about a superhero – we’re watching a television show about a super villain. Like many other Marvel baddies, David Haller isn’t an evil guy hellbent on world domination. He’s just a powerful figure driven by a very specific point of view. Or rather, views. It’s becoming increasingly obvious that Summerland will never be able control their newest recruit. In fact, this particular team of almost-X-Men look more and more like the only people capable of standing in his way. This ragtag group, this touchy-feely cult, this oddball crew whose powers have limited combat use, has to face down the monster they unleashed.

And it hurts. A lot. Because we know, and they know, that David is an okay guy. A sweet guy. Deep down. Under those monsters.